Source: www.TurfMagazine.com
Strategies from a California landscaper and irrigation expert.
For the third time in the state’s history, California is facing a water crisis that reaches far beyond a solitary dry spell. Now in its fourth straight year, this ongoing drought is forcing the California Department of Water Resources to declare a state of emergency in many areas of the state. The deterioration of the Sacramento-San Joaquin Delta, state water cutbacks, decreased snowfall, and climate change are contributing to a situation that threatens the very quality of life of Californians.
The projected outlook also remains bleak when population growth is taken into account. According to the Association of California Water Agencies, “state officials recently projected that California’s population will reach 50 million by 2032 and 60 million by 2050.” This will create a huge strain on the state’s already taxed water supply system. Of course, one has only to read the news to know many other states are also facing ongoing water shortages.
Fertigation
In the face of such a seemingly insurmountable problem and accompanying water restrictions, landscaping becomes an easy target, leaving many to wonder what the future will look like for an industry so intimately tied to water-use.
Yet a major solution may lie in fertigation, or fertilizing a yard through the irrigation system. The practice has historically been used almost exclusively at large commercial establishments such as golf courses and nurseries. But at my CA-based landscape firm, CK Water Systems and Landscape Development, I make fertigation systems available to residences, homeowners’ associations, and businesses throughout the Bay Area.
Our system is a bit different. It implements bio-stimulants, such as bacteria and fungi, instead of traditional fertilizer chemicals, such as nitrogen. A tank is installed in the main line of any irrigation system, then filled with water that is “spiked” with these bio-stimulants. Hooked up to the water line from a home, the tank provides the landscape with a dose of vital bio-stimulants every time the yard is watered.
Have you ever wondered why the forest does so well in a drought without irrigation and fertilizer? It’s because the forest has its own microbiology—living organisms, bacteria and fungi, otherwise known as bio-stimulants—which feed the plants on a continual basis. For example, there are certain bacteria that literally pluck nitrogen from the air and give it to the plant on a continual basis. Also, there’s a fungus that adheres to the root zone, making roots twice as long while also feeding the root moisture found in the soil. These are the same bio-stimulants we use to fill our fertilizer tanks.
Why fertigate as opposed to spreading traditional fertilizer and watering your landscape? This is where the water savings come in. A fertigation system can reduce water usage by as much as 20% to 60%. Put simply, plants that receive bio-stimulants on a regular basis simply don’t need as much water.
Also, the elimination of nitrogen creates water savings. The key ingredient in pellet fertilizer is nitrogen, of which only 20-30% gets absorbed. Adding nitrogen irregularly and in high doses creates stress and shock on the root zone, which creates an even greater need for water. Excess nitrogen also runs off into gutters and streams and is extremely harmful to the environment. The bio-stimulants used in fertigation have a 100% absorption rate, eliminating polluting runoff.
Installation of a fertigation system involves setting up an irrigation tank, irrigation lines, and a unit that prevents backflow, then troubleshooting pressure issues and points of connection. When we install a fertigation system, it includes a warranty on the tanks, then we provide consistent check-ups on both the system and the landscape’s health. We charge about $1,800 for installing a typical residential tank, with periodic tank fills around six times a year. For very large residences and small commercial sites, we charge around $3,900 for tank installations, with refills approximately eight times per year.
The efficiency of a fertigation system can be increased by using it in conjunction with a smart timer that measures a property’s particular microclimate, such as temperature, humidity, wind, and solar radiance. It then determines how to best water the yard efficiently. Utilizing additional measures such as rainwater catchment and graywater recycling (more on these later), today’s fertigation systems are twice as efficient as systems available just three years ago, and can cut down on water by 40% to 60% within the first year.
Rainwater Harvesting
Despite the drought, one thing we often come across in landscape projects is groundwater seeping into foundation drains. When this is encountered—which seems a major setback since water is a corrosive force—we instead turn this negative into a huge benefit. We reroute the groundwater through a series of French drain systems into a collection tank and reuse it for irrigation. Sometimes the groundwater is even reused for house water when we strap a UV filter to it.
Crystal Springs Reservoir supplies a majority of the water to the peninsula Bay area and San Francisco. This water is pumped and transferred hundreds of miles from the Hedgehog Reservoir. The Crystal Springs Reservoir continually leaches through a huge area in the peninsula including Millbrae, Hillsboro, Redwood City, and parts of Menlo Park. It’s in these locations where we run into groundwater on a very consistent basis, and we’re able to recollect groundwater that would be bound for the Bay and reuse it for people’s landscapes. In these instances, we have been able to take homes off the grid completely as far as water is concerned. We are also able to incorporate these large dissipator French drain systems into the landscape and have them pump to large underground fertigation storage tanks. So while the property owner never really sees any of these systems after completion, the water reuse is offering cost savings, and benefiting the aesthetics of the yard.
Graywater Recycling
Another thing we do to combat drought is graywater recycling. Graywater is a great resource because it’s water that would otherwise be sent down the drain to be treated to an already over-strained sanitation department. That, and it saves water, of course. The major drawback with this, however, is separating out the blackwater from the graywater since we have to open up the walls and piping of the client’s home. The ideal time to do this is when the homeowner is in the middle of a remodel. Then it’s very easy to separate the pipes and leave access to the graywater alone. After this is done, we send the water through a filter system, which can be another added benefit to the landscape.
We find a natural filtration system that is gravity fed and subterranean always works the best and is the most economical. This being said, there are also plenty of filters on the market with a pump that can create a pressurized irrigation system on a small level. (For more on graywater, see “Water Harvesting & Reuse”)
As a largely water-reliant industry, landscaping is now faced with different circumstances that require different measures. Water reclamation, graywater recycling, and fertigation are some of the most accessible ways for landscaping companies to meet the future, while still creating stunning properties.
Cartwright is the owner/operator of San Francisco-CA based CK Water Systems and Landscape Development. He was raised in and around the family business of landscape development. Educated in NY, Cartwright has traveled the world discovering irrigation methods forgotten by western cultures. In Australia, he received a degree in Ecology, was educated in graywater/rainwater catchment systems, and learned the benefits of bio-stimulants. From the Gobi deserts to the Cambodian jungles, Cartwright is well versed in all aspects of irrigation. He is a certified Water Conservation Manager, Certified Irrigation Technician, and is considered an authority on the subject.
CK Landscape is dedicated to creating landscapes of beauty and quality while saving the Bay Area millions of gallons of water. They are spearheading the movement concerning water conservation and landscape sustainability; and are always changing the industry process.
Click here to read more about water conservation in the lawn care and landscaping industry.
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